ERBB2 and breast cancer: In a meta-analysis by the EBCTCG, post-mastectomy radiotherapy for patients with axillary lymph nodes decreased the 10-year first recurrence rate by 10.6%, resulting in an 8.1% decrease in breast cancer mortality after 20 years.[39] The anti-HER2 therapy (mainly trastuzumab and pertuzumab) with chemotherapy led to dramatic improvements in the survival of patients suffering from HER2 positive breast cancer.[40]